User Manual
Publication date: July, 2006
Revision A2
141
Function name:
D-Type TOS
Function description:
IP TOS Priority affect TOS fields of IP header, you can find it has 8-bit
SERVICE TYPE field that specifies how the datagram should be handled. The
field could be divided into six subfields as follows, PRECEDENCE (3 bits), D-
Type (Delay Priority, 1 bit ), T-Type (Throughput Priority, 1bit), R-Type
(Reliability Priority, 1bit ), M-Type (Monetary Cost Priority, 1bit ), and UNUSED.
PRECEDENCE 3-bits can arrange 8 kinds of priorities corresponding to the
0~7 priority in the following priority diagram. TOS Delay Priority Mapping
works while D-TYPE in TOS field of IP header of the packets received by the
switch is configured.
Parameter description:
TOS Delay Priority Mapping:
Each Priority can select any of Queue 0 ~ Queue 3. In Default, Priority 0
is mapping to Queue 0, Priority 1 is mapping to Queue 0, Priority 2 is
mapping to Queue 1, Priority 3 is mapping to Queue 1, Priority 4 is
mapping to Queue 2, Priority 5 is mapping to Queue 2, Priority 6 is
mapping to Queue 3, and Priority 0 is mapping to Queue 3.